Rectangular fraction collector



Dec. 24, 1968 J. n. ALLINGTON RECTANGULAR FRACTION COLLECTOR Filed Oct. 27. 1966 6 Sheets-Sheet l 2312/ 2/ l I I QQGQX 5:: $5 2 I" 25' W .nmmum 2 Hun-nun m JOHN R. ALL/N670 INVENTOR.

Dec. 24, 1968 J. R. ALLINGTON 3,413,034

RECTANGULAR FRACTION COLLECTOR Filed CO1.- 27, 1965 6 Sheets-Sheet 2 III- vll m JOHN R. ILL/N670 INVENTOR.

,1968 J. R. ALLINGTON I 3,413,034

RECTANGULAR FRACTION COLLECTOR Filed 001;. 27, 1966 6 Sheets-Sheet 5 JOHN R. ALL/N670 INVENTOR.

Bvdww 1968 J. R. ALLINGTON 3,418,084

RECTANGULAR FRACTION COLLECTOR Filed Oct. 27. 1965 6 Sheets-Sheet 4 L J I JOHN R. ALL/NGTO/V INVENTOR.

Dec. 24, 1968 J. R. ALLINGT ON 3,413,034

RECTANGULAR FRACTION COLLECTOR Filed Oct. 27, 1965 6 Sheets-Sheet 5 JOHN R. ALL/N6 TON INVENT OR.

Dec. 24, 1968 J. R. ALLINGTON RECTANGULAR FRACTION COLLECTOR Filed Oct. 27, 1966 C 6 Sheets-Sheet 6 JOHN R. ALL/N670 INVENTOR.

BY v

United States Patent Office 3,418,084 Patented Dec. 24, 1968 3,418,084 RECTANGULAR FRACTION COLLECTOR John R. Allington, Lincoln, Nebr., assignor to Instrumentation Specialties Company, Lincoln, Nebr., a corporation of Nebraska Filed Oct. 27, 1966, Ser. No. 589,878 Claims. (Cl. 23259) This invention relates to a chemical fraction collector and more particularly to apparatus for carrying a plurality of test tubes in succession through a filling station.

Chemical fraction collectors are used for the collection of liquid samples from chromatographic apparatus for purposes of analysis. Certain fraction collectors comprise a turntable arranged to carry a plurality of test tubes in concentric or spiral rows. The turntable turns a few degrees after each sample collection to bring the next tube into the filling position. Such device requires considerable space and a group of test tubes cannot conveniently be removed until the entire fractionation run is completed. Other fraction collectors comprise an arrangement of shuttles, each carrying a plurality of test tubes and movable linearly through the filling station. Each shuttle is removable and can be used as a test tube rack. However, apparatus of this class presently available is of complex construction requiring several motors, levers and cams to move the shuttles, either from one magazine to another or around a continuous path.

A fraction collector made in accordance with this invention comprises a plurality of shuttles arranged in two rows Within two magazines formed in a common container. Each shuttle is provided with means for carrying a plurality of test tubes and is easily inserted into and removed from the container. The shuttles and the container are so constructed that movement of the shuttles through the filling stations and a subsequent transfer of shuttles from one to the other of the magazines requires the use of two simple spur gears, thereby resulting in manufacturing economy and greater reliability of service due to a minimum number of moving parts to be damaged mechanically or by spilled chemicals.

An object of this invention is the provision of a chemical fraction collector of novel construction involving a minimum number of parts.

An object of this invention is the provision of a chemical fraction collector comprising a plurality of identical shuttles for carrying test tubes, which shuttles are arranged in two rows in magazines formed in a container, means for automatically effecting a transfer of shuttles from one to the other magazine, and drive means for imparting an intermittent linear movement to the shuttles as they progress between the two magazines.

An object of this invention is the provision of a chemical fraction collector comprising a rectangular container divided into two magazines, a plurality of identical shuttles disposed in rows in the magazines, means forming transfer passageways at the ends of the magazines, means for simultaneously driving two shuttles through the transfer passageways in opposite directions and cooperating coupling means formed at the end of each shuttle, said coupling means automatically eliecting a coupling and decoupling of the end shuttles in each magazine to the said two shuttles when the latter occupy predetermined positions in the said passageways.

An object of this invention is the provision of apparatus for transporting test tubes or the like in succession through filling stations, which apparatus comprises a pair of magazines formed in a container, means forming transfer passageways at the ends of the magazines, a plurality of shuttles disposed in rows in the magazines and two reference shuttles initially disposed in the said passage ways, means for simultaneously moving the two reference shuttles through the passageways in opposite directions in a step-by-step manner thereby to position the associated test tubes in the filling stations, cooperating coupling means formed on the ends of the shuttles for automatically effecting a mechanical coupling and decoupling of the end shuttle of each magazine to the proximate reference shuttle when the latter is in predetermined position in the passageway, and cooperating means formed on the shuttles and the container for automatically effecting a transfer of the reference shuttles into the magazines.

These and other objects and advantages of the invention become apparent from the following description when taken with the accompanying drawings. It will be understood, however, that the drawings are for purposes of illustration and are not to be construed as defining the scope or limits of the invention, reference being had for the latter purpose to the claims appended hereto.

In the drawings wherein like reference characters denote like parts in the several views:

FIGURE 1 is a top plan view of a fraction collector made in accordance with one embodiment of this invention;

FIGURE 2 is an enlarged, top plan view of one of the shuttles;

FIGURE 3 is a cross-sectional view taken along the line IIIIII of FIGURE 2 and including one of the spur gears;

FIGURE 4 is a fragmentary, isometric view showing the hook member and camming surfaces formed at one end of the shuttle;

FIGURES 5-1O are enlarged fragmentary plan views showing the progressive movement of the shuttles from one to the other magazine when the apparatus is made as shown in FIGURE 1;

FIGURE 11 is similar to FIGURE 1 and shows the apparatus made in accordance with another embodiment of the invention; and

FIGURES 12-17 correspond to FIGURES 5-10 but showing the movement of the shuttles from one to the other magazine when the apparatus is made as shown in FIGURE 11.

Referring now to FIGURE 1, the apparatus comprises a shallow, rectangular container 10 having square, inner corners. Secured to the bottom of the container is a rectangular frame member 11, the end walls 12 and 13 being spaced a predetermined distance from the container front and rear walls 14 and 15, respectively. The chamber formed between the container side wall 16 and the left side wall 17, of the frame member, constitutes a left magazine, and the chamber formed between the container side wall 18 and the right side wall 19, of the frame member, constitutes a right magazine. The magazines are filled with identical shuttles, the end shuttles in the left magazine being identified by the capital letters B and D and the end shuttles in the right magazine being identified by the letters F and K. Two additional shuttles A and C are disposed in the spaces between the frame member and the container front and rear walls. For purposes of description, these spaces will be referred to as transfer passageways and the two shuttles disposed therein will be referred to as reference shuttles. Each transfer passageway has a width slightly greater than that of the shuttles to afford longitudinal sliding movement of the reference shuttles. In operation, the reference shuttles are moved, simultaneously, in opposite directions through the transfer passageways, the shuttles in the left magazine move laterally toward the container front wall 14, as indicated by the arrow a, and the shuttles in the right magazine move toward the container rear wall 15, as indicated by the arrow b.

Each shuttle is provided with means for carrying a plurality of test tubes, in upright positions, for receiving liquid from a chromatographic apparatus. For example, each shuttle may have formed therein a plurality of longitudinally-spaced bores for receiving the test tubes, several of such bores 20 and 21 being shown formed in the upper surfaces of the reference shuttles A and C, respectively. Alternatively, the bores may be omitted and each shuttle provided with suitable means for Securing a test tube rack thereto. As will be described hereinbelow, the reference shuttles are moved longitudinally through the transfer passageways in a step-by-step manner, through filling stations, identified, for example, by the letters 1 and 9". By means of suitable nozzles, liquid from the chromotographic apparatus may be directed into either or both of the two test tubes which occupy the filling stations. Thereafter, the reference shuttles A and C are moved in a step-by-step manner to bring succeeding test tubes into position for filling. The arrangement for automatically filling the test tubes is well known in the chromatographic technique. Before the last test tubes of these shuttles have been filled, the leading shuttles B and K, in each magazine, automatically are moved into alignment with the transfer passageways and mechanically coupled to the proximate reference shuttles A and C so that the test tubes carried by the said leading shuttles may be moved through the filling stations. The step-bystep movement of the two shuttles through the transfer passageways is effected by means of two spur gears 22 and 23 having teeth extending through openings formed in the container bottom and in mesh with gear racks formed in the bottom surfaces of the shuttles, each gear rack extending the full length of the shuttle bottom.

The construction of the shuttles is shown in FIG- URES 2-4 to which reference now is made. Here are shown, for example, ten bores 20 for accommodating ten test tubes. Referring to the left hand end of the shut-. tle, the side walls are tapered to a point forming the outer camming surfaces 25, 26 and the upper surface is recessed to form the upstanding hook member 27 and the complementary inner camming surfaces 28 and 29. The right hand end of the shuttle is of similar construction but reversely disposed, that is, the hook member 27 extends downwardly and the outer camming surfaces 25' and 26' lie on opposite sides of the shuttle center line 30 when taken with reference to the correspondingly numbered outer camming surfaces 25 and 26. It will be noted that the hook members are spaced from the apexeS of the inner camming surfaces. Also, as shown in FIG- URE 2, the pointed ends of the shuttle are offset to opposite sides of the center line 30. The described arrangement facilitates initiation of the camming action, as will be described below. Formed in the bottom surface of the shuttle, along the center line, is a gear rack 31, which rack extends the .full length of such surface. This gear rack is engaged by the spur gear 22 when the shuttle is disposed in the transfer passageway as, for example, the shuttle A shown in FIGURE 1. The two spur gears 22 and 23 are mechanically-coupled together and operated intermittently, by a suitable drive mechanism, whereby the two shuttles are moved longitudinally in a step-bystep manner in opposite directions. Referring again to FIGURES 24, each of the hook members 27, 27' extends somewhat beyond the median plane of the shuttle. Thus, when two shuttles are aligned end to end, the downwardly-extending hook member of one shuttle and the upwardly-extending hook member of the other shuttle may be brought into overlapping relationship, thereby to mechanically couple the shuttles together for simultaneous longitudinal movement. On the other hand, the camming surfaces of the shuttles serve as means for automatically transferring the shuttles from the transfer passageways into the magazines, as will now be described with reference to FIGURES -10.

In FIGURES 5l0, there are shown the container front wall 14 and side walls 16, 18, as well as the corresponding walls 12, 17 and 19 of the frame member, said frame member being secured to the container bottom 32. The test tube bores of the shuttles are omitted. For purposes of description, in FIGURE 5, the front reference shuttle A is shown more or less centrally positioned in the front transfer passageway. In this position, the shuttle A is sliding engagement with the end shuttles B and F, the shuttle B being the foremost shuttle in the left magazine and the shuttle F being the rearmost shuttle in the right magazine. The spur gear 22 is in mesh with the gear rack formed in the bottom surface of the shuttle A. Intermittent rotation of the gear results in a longitudinal step-by-step movement of the shuttle through the transfer passageway from left to right, as indicated by the arrow marked thereon.

When the shuttle A reaches the position shown in FIGURE 6, it permits the shuttle B to slide into place behind it, it being noted that the relatively-short, outer camming surface 25, of the shuttle B, now coincides with the relatively-short inner camming surface 28 of the shuttle A. It is here pointed out that when the shuttle A is in this position, the camming surfaces of the reference shuttle C (FIGURE 1), similarly engage the camming surface of the shuttle D, thereby forcing all of the shuttles in the left magazine to move toward the container front wall 14. As shown in FIGURE 6, the downwardly-extending hook member 27 of the shuttle B, is spaced from the upwardly-extending hook member 27 of the shuttle A.

As the shuttle A moves further to the right, the shuttle B slides into alignment with shuttle A. During such rela tively sliding movement of these shuttles, the hook member of one shuttle slides along the inner ramming surfaces of the other shuttle. Thus, when the two shuttles are in alignment, as shown in FIGURE 7, the hook members overlap each other and the shuttles A and B are mechanically-coupled together. Now, the shuttle A, driven :by the spur gear, draws the shuttle B along with it.

When the shuttle A reaches the position shown in FIG- URE 8, the spur gear 22 is in mesh with the gear rack formed in the bottom surface of the shuttle B, it being pointed out that the gear racks extend the full length of the shuttles whereby there is a smooth transfer of the spur gear teeth from one to the other shuttle without loss of shuttle motion. Now, the shuttle B drives the shuttle A ahead of it. As seen in FIGURE 8, the relatively-long outer camming surface 26' of the shuttle B coincides with the relatively-long inner camming surface 29 of the shuttle A. Although these coinciding camming surfaces of the two shuttles lie in a vertical plane which is angularly offset with respect to the shuttle axes, the left end portion of the shuttle A is confined between the container front wall 14 and the frame member front wall 12. Therefore, the shuttle A, pushed by the shuttle B, moves longitudinally.

Eventually, the shuttles reach the positions shown in FIGURE 9, wherein the tapered right end of the shuttle A engages the container side wall and the tapered left end of this shuttle is clear of the frame member side wall 19. Now, the slidably-engaged, coinciding camming surfaces 26 and 29 effect a camming action, resulting in a tilting of the shuttle A, as shown. Upon further movement of the shuttle B, its forward end slides in front of the shuttle A, thereby causing the latter to move into the right magazine, as shown in FIGURE 10. The shuttle B now occupies the initial position of shuttle A. The transfer movement of the shuttle A- into the right magazine, as shown in FIGURES 9 and 10, results in a forceful displacement of the shuttle F toward the rear of the right magazine. A similar action takes place at the rear end of the apparatus. Specifically, and with reference to FIGURE 1, the transfer shuttle C is driven to the left by the spur gear 23 and the camming surfaces of this shuttle cooperate with the camming surfaces of the rearmost shuttle D. At the same timethat the shuttles A and B are aligned, the shuttle C forces the shuttle D toward the front of the container. After the shuttle B is aligned with the shuttle A, the shuttle A (FIGURES 9 and 10), displaces the shuttles in the right magazine so that the foremost shuttle K (FIGURE 1), automatically couples to the shuttle C. Thereafter, the shuttles C and K move simultaneously, and in the same manner, as has been described with reference to the shuttles A and B.

It will now be apparent that two shuttles are driven through the transfer passageways in a step-by-step manner by the associated spur gears. Such movement of these two shuttles results in a displacement of the two rows 2f shuttles in the magazines in opposite directions. When these transfer shuttles occupy predetermined positions in the transfer passa eways, the ends of the foremost shuttles in each magazine automatically are coupled to the trailing ends of the associated transfer shuttle. Eventually, these foremost shuttles force the original reference shuttles into the magazines.

With continued reference to FIGURE 1, the spacing between the side walls 17 and 19, of the frame member (that is, the length of the transfer passageways) is related to the length of the shuttles so as to permit the simultaneous lateral displacement of the shuttles within each magazine as the transfer shuttles move through the filling stations and into the magazines. The space within the frame member 11 may be utilized for the drive motor, gearing and other components required to drive the shuttles, in a step-by-step manner, through the filling stations and in synchronism with a suitable timing or other mechanism for filling the test tubes. It will be apparent that the container may have a size to accommodate a desired number of shuttles of a given thickness and length.

Reference now is made to FIGURE 11, which corresponds to FIGURE 1 but shows another embodiment of the invention. Here, the container 10" is the same as that shown in FIGURE 1 except that the four inner corners 34-37 are oblique surfaces. The outer corners 3841, of the frame member 11', also are oblique surfaces and parallel to the proximate corners of the container. The number, construction and arrangement of the shuttles, as well as the spur gears, remains the same. In the FIGURE 11 arrangement, there is no tilting of the reference shuttles as they pass out of the transfer passageways into the magazines, as will now be descri ed with reference to FIGURES 12-17, which figures correspond to FIGURES 5-10.

In FIGURE 12, the reference shuttle A is in the front transfer passageway with the spur gear 22 in mesh with the shuttle gear rack. When the shuttle A is moved to the position shown in FIGURE 13, it permits the shuttle B to slide into place behind it. At this point, the relatively-short, outer camming surface 25' of the shuttle B is in sliding engagement with the relatively-short, inner camming surface 28 of the shuttle A. At the same time, 1

the relatively-long, outer camming surface 26 of the shuttle B is in sliding engagement with the oblique surface 35 of the container. Also, the downwardly-extending hook member 27 of the shuttle B is spaced from the upwardlyextending hook member 27 of the shuttle A. It will be apparent that the camming surface 26 will slide along the container oblique surface 35 as the shuttle A moves further to the right. thereby resulting in an oblique movement of the shuttle B.

When the shuttle A is in the position shown in FIGURE 14, the shuttle B will be in engagement with the container front wall 14 and the hook members of these shuttles will overlap each other, thereby mechanically coupling the shuttles together. Now, the shuttle A, driven by the spur gear, draws the shuttle B along with it. Just prior to the time when the shuttles reach the positions shown in FIGURE 15, the spur gear 22 passes out of mesh with the gear rack of shuttle A and into mesh with the gear rack of shuttle B. At this point, the relativelylong, outer camming surface 26, of the shuttle B, en-

Ill

gages the relatively-long, inner camming surface 29 of the shuttle A so that soon thereafter the relatively-short, outer camming surface 25 of the shuttle A strikes the coinciding oblique surface 36 of the container, as shown in FIGURE 15. As the shuttle B now continues to push the shuttle A, the latter moves toward the magazine in an oblique direction, as indicated by the arrow. However, due to the particular angular disposition of the two shuttle camming surfaces 26" and 29, on the one hand, and the precisely reverse disposition of the shuttle A camming surface 25 and the container surface 36, on the other hand, the entire shuttle A moves obliquely toward and into the magazine, that is, there is no tilting f the shuttle A as shown in the corresponding view of FIGURE 9. The oblique corner 40, of the frame member, has the same angular disposition as the relatively-short, outer camming surface 25 of the shuttle A. Thus, as the shuttle A is pushed further by the driven shuttle B, the shuttle A camming surface 25 first engages and then slides along the oblique surface 40 and, eventually, the shuttle A is moved into the magazine as shown in FIG- URE 17. Now, shuttle B has taken the place of shuttle A in the transfer passageway and is in sliding engagement with the shuttle A and the now foremost shuttle B1 of the left magazine. During the oblique movement of the shuttle A, from the position shown in FIGURE 15 to the position shown in FIGURE 17, there occurs an automatic disen agement of the reversely-disposed hook members. A similar action to that just described with reference to FIGURES 12l7 takes place at the rear of the apparatus involving the shuttles D, C and K shown in FIGURE 11.

Having now described the invention, those skilled in this art will be able to make various changes and modifications without thereby departing from the spirit and scope of the invention as recited in the following claims.

I claim:

1. Apparatus comprising,

(a) two spaced, parallel chambers having front and rear transfer passageways formed at the ends,

(b) a plurality of shuttles having complementary camming surfaces formed at the ends thereof, two reference shuttles being disposed in othe passageways and the remaining shuttles disposed in rows in the chambers, one reference shuttle being initially in end engagement with the rearmost shuttle disposed in one chamber and the other reference shuttle being initially in side engagement with the rearmost shuttle in the other passageway, and

(c) drive means for simultaneously moving the said reference shuttles through the passageways in opposite directions, the camming surfaces of the engaged shuttles effecting a lateral displacement of such rearmost shuttle in its chamber.

2. The invention as recited in claim 1, including gear racks formed in the bottom surfaces of the shuttles and extending the full length of such surfaces and wherein the said drive means comprises gears which mesh with the gear racks of the shuttles in the transfer pasageways, and including hook members extending in opposite directions from the ends of each shuttle, the hook member of the foremost shuttle in said one chamber automatically coupling to the hook member of the said other reference shuttle in its chamber.

3. Apparatus comprising,

(a) a container divided into first and second parallel magazines,

(b) means forming front and rear transfer passageways at the ends of and between the magazines,

(0) a plurality of shuttles having tapered ends constituting camming surfaces, two reference shuttles being initially disposed in the passageways and the remaining shuttles being disposed in rows in the magazines, one reference shuttle being initially in axial alignment with the rearmost shuttle in the first magazine and the other reference shuttle being initially in side engagement with the rearmost shuttle in the second magazine,

(d) first drive means for moving the said one reference shuttle along the rear passageway into end engagement with the rearmost shuttle in the first magazine, the engaged camming surfaces of these shuttles effecting a lateral displacement of such rearmost shuttle in the magazine, and

(e) second drive means simultaneously moving the other shuttle along the front pasageway in a direction opposite to that of the said one reference shuttle.

4. The invention as recited in claim 3, including cooperating coupling means formed on the ends of each shuttle, which coupling means mechanically couples an end of the foremost shuttle of said first magazine to the trailing end of the other reference shuttle upon lateral displacement of the rearmost shuttle in the first magazine.

5. The invention as recited in claim 4, wherein the said coupling means comprises hook members extending in opposite direction from the ends of each shuttle, and in which said shuttles include means for supporting a plurality of test tubes in upright position and have a gear rack formed in the bottom surface thereof extending the full length of said surface, and wherein said first and second drive means comprise gears which mesh with the gear racks of the shuttles disposed in said passageways.

6. Apparatus comprising,

(a) a rectangular container divided into first and second magazines,

(b) means forming front and rear transfer passageways at the ends of and between the magazines,

(0) a plurality of shuttles having tapered ends constituting camming surfaces, first and second reference shuttles being disposed in the passageways and the remaining shuttles being disposed in rows in the magazines, the first reference shuttle being initially in end engagement with the rearmost shuttle of first magazine and the rearmost shuttle of the second magazine being initially in side engagement with the second reference shuttle, and

((1) drive means for simultaneously moving the reference shuttles in opposite directions through the passageways, the arrangement being such that upon movement of the two reference shuttles the first reference shuttle presses the engaged rearmost shuttle against the container side wall after which the engaged camming surfaces of these shuttles effect a lateral displacement of such rearmost shuttle in the first magazine, and the foremost shuttle in the first magazine is moved into axial alignment with the second reference shuttle during the lateral displacement of said rearmost shuttle of the first magazine.

7. The invention as recited in claim 6, including oblique surfaces formed at the inner corners of the container, said oblique surfaces having an angular orientation coin ciding with that of the camming surfaces formed on the ends of the shuttles, wherein a camming surface of the rearmost shuttle of the first magazine slidably engages one of the oblique surfaces during lateral displacement of such rearmost shuttle in its magazine, and wherein a camming surface of the foremost shuttle in the first magazine slidably engages another of the oblique surfaces during movement of such foremost shuttle into alignment with the second reference shuttle.

8. Apparatus comprising,

(a) a rectangular container having oblique camming surfaces formed at the inner corners thereof,

(b) a frame member secured to the container, said member having side walls spaced from the container side walls to form a pair of magazines and end walls spaced from the other container Walls to form a pair of transfer passageways,

(c) a plurality of shuttles having tapered ends constituting camming surfaces, hook members extending from the tapered ends in oposite directions and a gear rack formed in the bottom surface and extending the full length of such surface; two reference shuttles being initially disposed in the said passageways and the remaining shuttles disposed in rows in the magazines, one reference shuttle being initially in engagement with the rearmost shuttle in one magazine and the other reference shuttle being initially in side engagement with the foremost shuttle in the other magazine, and

(d) a pair of driving gears carried by the container and in mesh with the gear racks of the reference shuttles, said gears simultaneously driving the reference shuttles along the passageways in opposite directions, the camming surfaces of the shuttles and the said oblique camming surfaces being so arranged that, upon movement of the reference shuttles through the passageways, the said rearmost shuttle engages one oblique surface and is displaced laterally in the said one magazine, simultaneously in said foremost shuttle is moved obliquely out of the first magazine and into axial alignment with the other reference shuttle, the hook member of the said foremost shuttle mechanically couples to the hook member of the second reference shuttle as the foremost shuttle moves into alignment with the second reference shuttle, the gear rack of the second reference shuttle passes out of mesh with the associated gear as the gear rack of the said foremost shuttle moves into mesh with such gear, after which the said foremost shuttle pushes the second reference shuttle into engagement with a diagonally-opposed oblique surface and obliquely into the other magazine.

9. The invetnion as recited in claim 8, including means for supporting a plurality of test tubes in upright posi tions on each shuttle.

10. A shuttle, or the like, comprising,

(a) an elongated body having parallel side walls terminating in tapered end portions having apexes offset in oposite directions with reference to the longitudinal center line of said body.

(b) means forming a set of tapered surfaces at the end portions of said body, each set of tapered surfaces being parallel to the proximate one of said end portions and having an apex spaced inwardly thereof,

(c) hook members extending in reverse directions from the apexes of said tapered end portions of the body, and

((1) means forming a longitudinally-extending gear rack on one surface of the said body.

References Cited UNITED STATES PATENTS 1,73 8,039 12/1929 Cope et al 263-6 1,837,605 12/1931 Baker 198-85 3,168,124 2/1965 Lenkey 141-284 3,221,781 12/1965 Forsstrom 141-130 3,233,640 2/1966 Van Der Graaf 141-130 JAMES H. TAYMAN, JR., Primary Examiner.

US. Cl. X.R. 

1. APPARATUS COMPRISING, (A) TWO SPACED, PARALLEL CHAMBERS HAVING FRONT AND REAR TRANSFER PASSAGEWAYS FORMED AT THE ENDS, (B) A PLURALITY OF SHUTTLES HAVING COMPLEMENTARY CAMMING SURFACES FORMED AT THE ENDS THEREOF, TWO REFERENCE SHUTTLES BEING DISPOSED IN OTHER PASSAGEWAYS AND THE REMAINING SHUTTLES DISPOSED IN ROWS IN THE CHAMBERS, ONE REFERENCE SHUTTLE BEING INITIALLY IN END ENGAGEMENT WITH THE REARMOST SHUTTLE DISPOSED IN ONE CHAMBER AND THE OTHER REFERENCE SHUTTLE BEING INITIALLY IN SIDE ENGAGEMENT WITH THE REARMOST SHUTTLE IN THE OTHER PASSAGEWAY, AND 